1. Field of the Invention
This invention relates to a porous, static pressure air bearing device in a dentist's handpiece.
2. Description of the Prior Art
In the dentist's handpiece of the type using the conventional air bearing, the air bearing portion employed therein has taken the form of an air bearing wherein a number of fine apertures of the orifice type or of the inherently compensated type are formed in the bearing portion. These types of bearings have suffered from two disadvantages. One of them is that forming a number of fine apertures in the bearing portion is considerably difficult and inefficient. The other disadvantage is that the thrust load capacity is relatively low because the thrust bearing taking the load in the thrust direction of the rotatable shaft is formed by air leaving the radial bearing section.